Exit strategies from a lockdown are considerably more granular than throwing a simple lockdown on/off switch.
As an example, The Tony Blair Institute for Global Change has recently published a paper, Suppression Exit Strategies: Options for Lifting Lockdown Measures in the UK, which has been generally well received.
institute.global
I've not read it in any detail, but it seems to provide a helpful overview of the different possible strategies, how they'd work, and what the pros and cons are.
However it's done, various economies are going to have reopen gradually, one sector at a time, with manufacturing and building restarting before retail, and retail before tourism, bars and restaurants, and so much will depend on access to reliable testing.